Credentials have become a bit meaningless these days. If anyone says, trust me, I am "this title", in most cases they either don't have the title or their title is meaningless because they don't know what they are talking about even if they have it. Anyone who knows what they are talking about does not need to invoke their title and won't. They can explain it to a person. The throwing around of titles is a shortcut to ending a conversation or argument that isn't going the right way for the person throwing around their title. The only scenario where a legitimate person may throw around a title would be if the person they are arguing with thinks they know the subject matter but doesn't, and the person being talked to is so dumb, there is no point in continuing the conversation as it is clear they won't understand anything you tell them. But even then, it's better to say "you clearly don't know what you're talking about and I'm not going to waste my time trying to explain it to you" then to arrogantly throw around a title since throwing ones title around is a really bad habit to get into to. For me, someone just throwing their title to win an argument without providing any supporting information is a clear red flag. Automatically makes me suspicious that they don't know what they are talking about.

I knew a guy who was doing a study for his Master's thesis. Put a lot of effort into it. Then, once he was done, his professor put another guy's name as the primary author on the study implying that this other guy had done most of the work. That guy had in fact done no work and almost certainly didn't know anything about the study material yet was given credit for it. And this was over 10 years ago, academia has become more corrupt since then. Not sure why the professor did it, but both the professor and the student who had done no work were Jewish. Ethnicity/religion may have had nothing to do with it, the professor may have just accepted a bribe. But I would speculate that maybe there were some family or political ties between them. The reason the guy told me and a bunch of people was because he worked really hard on that study and was proud of his work and to have his credit stolen like that really pissed him off.